Lateral Arm Numbness and Weakness: Consider Axillary Nerve Dysfunction

At the Centeno-Schultz Clinic we acknowledge that shoulder pain can compromise quality of life and athletic endeavors.

Our online book, Ortho 2.0 highlights a systemic evaluation of joint pain and dysfunction.  The approach is termed SANS.

The N is SANS denotes nerve dysfunction.

Axillary nerve dysfunction can be a cause of lateral arm numbness and shoulder weakness.

The Axillary nerve arises from the posterior cord of the brachial plexus, C5 and C6.

Course:  It crosses the antero-inferior aspect of the subscapularis muscle, passes behind the arm through the quadrilateral space, winding around the neck of the humerus ending in two major trunks:  anterior and posterior trunk.

Innervation:  Teres Minor and Deltoid

Sensory: Lateral deltoid also known as the regimental badge area.

Injury can occur at several sites along the nerve path:

Origin of the posterior cord

Anterior-inferior aspect of the subscapularis muscle

Quadrilateral Space:

The quadrilateral space is bounded superiorly by the teres minor muscle, inferiorly by the teres major muscle, medially by the long head of the triceps, and laterally by the humeral shaft.

Common presentation is dull intermittent ache or pain that is localized in the posterior and lateral shoulder.  Symptoms are exacerbated by active and resisted abduction and external rotation of the humerus.

Quadrilateral space syndrome is an affliction of middle-aged men and it presents classically in the throwing athlete and those with a history rotator cuff surgery.

Ultrasound examination is can be significant for atrophy of the teres minor muscle which is illustrated below.

 injury at several sitesgin from the posterior cordAnteroinferior aspect of the subscapularis muscle and shoulder capsuleQuadrilateral space

Acromioclavicular Joint Pain: Prolotherapy, PRP and Stem Cells

The acromioclavicular  (AC) joint is a small joint on the top portion of the shoulder.   The joint created by the end of the clavicle (collar bone) and the winged protrusion of the shoulder blade (acromion).  The AC joint allows the ability to raise the arm above the head.

The joint is stabilized by three ligaments:  acromioclavicular ligament, coracoacrominal ligament and coracoclavicular ligament

At the Centeno-Schultz Clinic AC joint injuries are graded  using the Rockwood scale.
Type I:
– sprain of joint with out a complete tear of either ligament.  The ligament is intact but stretched.
– Type II:
– tear of AC ligaments w/ coracoclavicular ligaments intact;
– will not show marked elevation of lateral end of clavicle;
– Type III:
– in this injury both AC & CC ligaments are torn;
– > 5 mm elevation of AC joint w/o weights is consistent w/ severe type II or a type III injury.

MSK ultrasound is utilized in the treatment of AC joint injuries given that both the joint and the supporting ligaments require treatment.  The perils of blind injections have been discussed previously.  Prolotherapy, Regenexx SCP and  Regenexx SD has been successful in the treatment of AC joint injuries at the Centeno-Schultz Clinic.

When in Doubt, Cut it Out

Patients are seeking alternatives to shoulder replacement surgery with increasing frequency.  Patients are concerned with complications, death and signficant downtime associated with shoulder replacements. 

The shoulder is a complex joint composed of tendons, ligaments, muscles and cartilage on the articulating surfaces.  Pain can arise from any or all of these structures.  At the Centeno-Schultz Clinic we are committed to identifying the principal source of pain in patients so a successful treatment regimen can be implemented.  Regrettably this is a universal practice.  DS is a case in point.

DS is an active 62 y/o rancher who sought a second opinion.  He had a 6 month history of left shoulder pain which was constant in duration, progressive in duration, principally located in the posterior shoulder without any radiations.  Aggravating factors including lifting whereas alleviating factors included rest and sleep.  DS had been evaluated by a surgeon and was identified as a suitable candidate for total shoulder replacement. DS had not undergone any conservative to date: no physical therapy, massage or myofasical deactivation.  X-ray was signficant for narrowing of the joint space.

DS and I were concerned that no conservative therapy had been undertaken.  Additionally the only study to date was an x-ray which examines bone and does not evaluate tendon, ligament or cartilage.  An MRI was ordered which was signficant for severe tendinosis of two of the rotator cuff tendons and arthritis of the shoulder joint.  DS declined the replacement and underwent two MSK US guided injections into the rotator cuff tendons and reports 65% improvement to date.  He is scheduled for additional treatment but remains active on his ranch without signficant limitations. 

Bottom Line:  Pain can arise from many different structures and can often times be treated successfully with non surgical regenerative treatments.